What a brand campaign protects
A brand campaign defends the moment of highest intent in your entire funnel: someone typing your name into Google. That person already knows you, was probably sent there by your other marketing, and is one click from buying.
Without a brand campaign, that search result is open inventory. Competitors can bid on your name and place their ad above your organic listing, intercepting buyers your other channels paid to create. Because brand clicks cost a fraction of non-brand clicks, the defense is one of the cheapest insurance policies in paid search. A small daily budget is usually enough, because the auction for your own name is one you should rarely lose.
The measurement caveat that matters
Brand campaigns capture demand that other channels created, so their ROAS looks spectacular and flatters the account average. A buyer who searched your name after seeing your product was already on the way; the brand click just collected the credit.
This is why brand and non-brand performance must be separated in reporting. Blended ROAS hides whether the non-brand spend, the part that grows the business by reaching people who have never heard of you, is working. An account average propped up by cheap brand conversions can disguise a non-brand program that loses money.
When skipping brand is the right call
Skip brand campaigns only in two situations: nobody searches your name yet, or no competitor bids on it. A new store with near-zero brand search volume has nothing to defend, and budget is better spent creating demand than protecting demand that does not exist.
Both conditions change, so recheck quarterly. Brand search volume grows as your marketing works, and competitors tend to discover your name at exactly the moment it becomes worth bidding on. The day a rival's ad sits above your organic listing is the day the brand campaign earns its budget.